A typical computer system 10, as shown in FIG. 1, includes several components that are collectively used by a user to perform various functions such as, for example, preparing and generating a document with a word processor application. With the computer system 10, the user may input data to a computing portion 12 using peripheral devices such as a keyboard 14 or a mouse 16. Data may also be provided to the computing portion 12 using data storage media, e.g., a floppy disk or a CD-ROM (not shown). The computing portion 12, using memory and other internal components, processes both internal data and data provided to the computing portion 12 by the user to generate data requested by the user. The generated data may be provided to the user via, for example, a display device 18 or a printer 20.
The computing portion 12 of a computer system typically includes various components such as, for example, a power supply, disk drives, and the electrical circuitry required to perform the necessary and requested operations of the computer system. As shown in FIG. 2, the computing portion 12 may contain a plurality of circuit boards 22, 24, 26, 28 on which various circuit components are implemented. For example, a computing portion designed to have enhanced sound reproducing capabilities may have a circuit board dedicated to implementing circuitry that specifically operates to process data associated with the reproduction of sound.
In FIG. 2, the components of exemplary circuit board 22 are shown. A crystal oscillator 30 provides a reference of time to various integrated circuit (IC) packages 32, 34, 36, 38, 40, 42 that are connected onto the circuit board 22. Those skilled in the art will recognize that the integrated circuit packages 32, 34, 36, 38, 40, 42 may be used to house and support various types of integrated circuits (e.g., application specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), microprocessors, and digital logic chips). The integrated circuit packages 32, 34, 36, 38, 40, 42 communicate with one another, i.e., pass data, using wires or traces of conductive material (e.g., copper or gold) (shown, but not labeled) embedded in the circuit board 22.
Those skilled in the art will recognize that the integrated circuits packages 32, 34, 36, 38, 40 shown in FIG. 2 serve to protect and support fragile and highly sensitive semiconductor dies on which actual integrated circuits are fabricated. For example, a semiconductor die having a specific type of integrated circuit fabricated thereon may be electrically packaged and housed by an integrated circuit package so as to be protected from high loads and adverse ambient conditions. Further, those skilled in the art will recognize that an integrated circuit package may be designed to provide signal and power distribution to the integrated circuit contained therein. Further still, those skilled in the art will recognize that an integrated circuit package may be beneficial for dissipating heat generated by the integrated circuit contained therein.
Still referring to FIG. 2, the integrated circuit packages 32, 34, 36, 38, 40, 42 serve as electrical interfaces between the integrated circuits fabricated on the semiconductor dies therein and the circuit board 22. As described below with reference to FIGS. 3 and 4, an integrated circuit package, such as any of the ones shown in FIG. 2, may be electrically connected to a substrate (e.g., circuit board 22 in FIG. 2) in any of a variety of ways.
FIG. 3 shows one type of an integrated circuit package referred to and known in the art as a “chip-on-board” package 50. In FIG. 3, a semiconductor die 52 having an integrated circuit fabricated thereon is disposed on a substrate 54 such that an inactive side 55 of the semiconductor die 52 faces the substrate 54 and is attached to the substrate 54 via an adhesive layer 56. Thus, an active side 58 of the semiconductor die 52 (i.e., the side of the semiconductor die 52 through which electrical activity necessary for proper operation of the semiconductor die 52 takes place) faces “up,” or away from the substrate 54. The active side 58 of the semiconductor die 52 is electrically connected to the substrate 54 by wire bonds 60. The wire bonds 60 are used for power and/or signal distribution. Further, an overfill material (not shown) may be disposed over the wire bonds 60 and the semiconductor die 52 to seal, fixate, and protect the wire bonds 60 and the semiconductor die 52 from, for example, environmental dangers (e.g., dust, moisture, etc).
FIG. 4 shows another type of an integrated circuit package referred to and known in the art as a “flip-chip” package 70. In FIG. 4, a semiconductor die 72 is disposed on a substrate 74 such that an inactive side 76 of the semiconductor die 72 faces away from the substrate 74. Thus, an active side 78 of the semiconductor die 72 faces “down,” or toward the substrate 74. The active side 78 of the semiconductor die 72 is electrically connected to the substrate 74 via solder balls (e.g., C4 solder balls) or bumps 80. The solder balls or bumps 80 are used for power and/or signal distribution. Further, in order to enhance the structural integrity of the flip-chip package 70, an underfill material (not shown) may be disposed in the gaps between the semiconductor die 72 and the substrate 74.